A249435 a(1) = 0, after which one less than prime powers p^m with exponent m >= 2.

0, 3, 7, 8, 15, 24, 26, 31, 48, 63, 80, 120, 124, 127, 168, 242, 255, 288, 342, 360, 511, 528, 624, 728, 840, 960, 1023, 1330, 1368, 1680, 1848, 2047, 2186, 2196, 2208, 2400, 2808, 3124, 3480, 3720, 4095, 4488, 4912, 5040, 5328, 6240, 6560, 6858, 6888, 7920, 8191, 9408, 10200, 10608, 11448

Offset

1,2

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Formula

a(n) = A025475(n) - 1.

Prog

(Scheme) (define (A249435 n) (- (A025475 n) 1))
(PARI) list(lim)=my(v=List([0])); lim=lim\1+1; for(m=2, logint(lim, 2), forprime(p=2, sqrtnint(lim, m), listput(v, p^m-1))); Set(v) \\ Charles R Greathouse IV, Aug 26 2015

Crossrefs

One less than A025475.

Subsequence of A181062 and also a subsequence of A249433 (after the initial zero).

Union of sequences A000225, A024023, A024049, A024075, A024127, etc. without their term a(1).

Apart from the first term, subsequence of A045542.

Sequence in context: A309197 A076683 A045542 * A192120 A031404 A263519

Adjacent sequences: A249432 A249433 A249434 * A249436 A249437 A249438

Keyword

nonn

Author

Antti Karttunen, Nov 02 2014

Status

approved